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Due to its effectiveness and affordability, solar Photovoltaic (PV) systems are now being employed more and more in many application systems. The biggest challenge is still getting the most energy out from PV panels in a variety of climatic situations. In order to achieve the maximum energy production, several optimization-based MPPT controlling techniques have been developed in traditional works. However, it has significant issues with low convergence, computational complexity, a long time needed to find the best solution, and inefficiency. As a result, the goal of this research is to implement a novel and hybrid optimization technique, named as, Prairie Dog Optimization Algorithm (PDOA) + Mongoose Optimization (MO) for extracting the highest possible energy from PV panels. The original contribution of this work is to incorporate the functions of two different and recently developed optimization techniques for MPPT controlling. For this purpose, the PDOA and MO algorithms are taken into account, and the hybridized PDOA+MO provides the benefits of fast convergence, increased tracking efficiency, and reduced tracking time. The high gain Luo DC-DC converter is also used to increase PV's output power and voltage while minimising switching and conduction losses. Consequently, the voltage source inverter is used to suppress the level of harmonics for providing the quality improved AC output to the grid system. The suggested PDOA+MO algorithm's effectiveness and power tracking performance are validated through a thorough simulation analysis using a variety of parameters.

Deletions or variants of the STRC gene coding for stereocilin cause congenital bilateral mild-to-moderate sensorineural hearing loss without vestibular disorder: DFNB16. Stereocilin is a protein present in vestibular kinocilia embedded in the otoconial membrane of the utricular macula. Benign paroxysmal positional vertigo (BPPV) is a rare form of vertigo in children. The present study reports recurrent positional vertigo in two DFNB16 siblings.Two patients, 10 and 15 years old, presented with recurrent disabling positional vertigo episodes, triggered by turning over in bed, with a falling sensation. The diagnosis of right posterior canal BPPV was confirmed on Dix-Hallpike maneuvers in one of the patients. Variations in the response of ocular vestibular-evoked myogenic potentials were observed. Probable BPPV was diagnosed in the second patient. Their other two siblings did not have hearing loss or vertigo.The absence of stereocilin due to homozygous deletions of the STRC gene in DFNB16 patients can cause vestibular dysfunction, including BPPV.

The Human Epidemiology and Response to SARS-CoV-2 (HEROS) is a prospective multi-city 6-month incidence study which was conducted from May 2020-February 2021. The objectives were to identify risk factors for SARS-CoV-2 infection and household transmission among children and people with asthma and allergic diseases, and to use the host nasal transcriptome sampled longitudinally to understand infection risk and sequelae at the molecular level. To overcome challenges of clinical study implementation due to the coronavirus pandemic, this surveillance study used direct-to-participant methods to remotely enroll and prospectively follow eligible children who are participants in other NIH-funded pediatric research studies and their household members. Households participated in weekly surveys and biweekly nasal sampling regardless of symptoms. The aim of this report is to widely share the methods and study instruments and to describe the rationale, design, execution, logistics and characteristics of a large, observational, household-based, remote cohort study of SARS-CoV-2 infection and transmission in households with children. The study enrolled a total of 5,598 individuals, including 1,913 principal participants (children), 1,913 primary caregivers, 729 secondary caregivers and 1,043 other household children. This study was successfully implemented without necessitating any in-person research visits and provides an approach for rapid execution of clinical research.

Carole A. Miller, M.D., was born (May 7, 1939) and raised in Kalamazoo, Michigan. She obtained her undergraduate and medical degrees at the Ohio State University. She went on to complete her neurosurgical training at the Ohio State University Medical Center. After her first faculty role at the University of Michigan (1971), she returned to the Ohio State University Medical Center (1975) where she spent nearly 4 decades. She thrived in the specialty, achieving in every facet of academic practice including scientific contributions, graduate medical education, clinical care, and leadership roles within her academic department, locally, and at the national level of organized neurosurgery. Dr. Miller passed away peacefully, on October 28, 2015, after a courageous battle with cancer. Based on her essential programmatic and specialty-related contributions, she is remembered as the 'founding mother' of neurosurgery at the Ohio State University.

Importance Sepsis is a common syndrome with substantial morbidity and mortality. A combination of vitamin C, thiamine, and corticosteroids has been proposed as a potential treatment for patients with sepsis. Objective To determine whether a combination of vitamin C, thiamine, and hydrocortisone every 6 hours increases ventilator- and vasopressor-free days compared with placebo in patients with sepsis. Design, setting, and participants Multicenter, randomized, double-blind, adaptive-sample-size, placebo-controlled trial conducted in adult patients with sepsis-induced respiratory and/or cardiovascular dysfunction. Participants were enrolled in the emergency departments or intensive care units at 43 hospitals in the United States between August 2018 and July 2019. After enrollment of 501 participants, funding was withheld, leading to an administrative termination of the trial. All study-related follow-up was completed by January 2020. Interventions Participants were randomized to receive intravenous vitamin C (1.5 g), thiamine (100 mg), and hydrocortisone (50 mg) every 6 hours (n = 252) or matching placebo (n = 249) for 96 hours or until discharge from the intensive care unit or death. Participants could be treated with open-label corticosteroids by the clinical team, with study hydrocortisone or matching placebo withheld if the total daily dose was greater or equal to the equivalent of 200 mg of hydrocortisone. Main outcomes and measures The primary outcome was the number of consecutive ventilator- and vasopressor-free days in the first 30 days following the day of randomization. The key secondary outcome was 30-day mortality. Results Among 501 participants randomized (median age, 62 [interquartile range {IQR}, 50-70] years; 46% female; 30% Black; median Acute Physiology and Chronic Health Evaluation II score, 27 [IQR, 20.8-33.0]; median Sequential Organ Failure Assessment score, 9 [IQR, 7-12]), all completed the trial. Open-label corticosteroids were prescribed to 33% and 32% of the intervention and control groups, respectively. Ventilator- and vasopressor-free days were a median of 25 days (IQR, 0-29 days) in the intervention group and 26 days (IQR, 0-28 days) in the placebo group, with a median difference of -1 day (95% CI, -4 to 2 days; P = .85). Thirty-day mortality was 22% in the intervention group and 24% in the placebo group. Conclusions and relevance Among critically ill patients with sepsis, treatment with vitamin C, thiamine, and hydrocortisone, compared with placebo, did not significantly increase ventilator- and vasopressor-free days within 30 days. However, the trial was terminated early for administrative reasons and may have been underpowered to detect a clinically important difference. Trial registration ClinicalTrials.gov Identifier: NCT03509350.

Heimler syndrome is a rare syndrome associating sensorineural hearing loss with retinal dystrophy and amelogenesis imperfecta due to PEX1 or PEX6 biallelic pathogenic variations. This syndrome is one of the less severe forms of peroxisome biogenesis disorders. In this chapter, we will review clinical, biological, and genetic knowledges about the Heimler syndrome.

We received so many biographies of women neurosurgery leaders for this issue that only a selection could be condensed here. In all of them, the essence of a leader shines through. Many are included as “first” of their country or color or other achievement. All of them are included as outstanding—in clinical, academic, and organized neurosurgery. Two defining features are tenacity and service. When faced with shocking discrimination, or numbing indifference, they ignored it or fought valiantly. When choosing their life’s work, they chose service, often of the most neglected—those with pain, trauma, and disability. These women inspire and point the way to a time when the term “women leaders” as an exception is unnecessary.—Katharine J. Drummond, MD, on behalf of this month’s topic editors

Christos Theophanous,1 Bobeck S Modjtahedi,2,3 Michael Batech,4 David S Marlin,1 Tiffany Q Luong,4 Donald S Fong2–4 1Department of Ophthalmology, Southern California Medical Group, Los Angeles, CA, USA; 2Department of Ophthalmology, Southern California Permanente Medical Group, Baldwin Park, CA, USA; 3Eye Monitoring Center, Kaiser Permanente Southern California, Baldwin Park, CA, USA; 4Department of Research and Evaluation, Southern California Permanente Medical Group, Pasadena, CA, USA Purpose: To evaluate the prevalence and risk factors for pediatric myopia in a contemporary American cohort. Methods: A cross-sectional study of pediatric patients enrolled in the Kaiser Permanente Southern California health plan was done. Eligible patients were 5- to 19-years old between January 1, 2008, through December 31, 2013, and received an ophthalmologic or optometric refraction. Electronic medical records were reviewed for demographic data, refraction results, and exercise data. Prevalence and relative risks of myopia (defined as ≤-1.0 diopter) were characterized. Age, sex, race/ethnicity, median neighborhood income, and minutes of exercise per day were examined as risk factors. Results: There were 60,789 patients who met the inclusion criteria, of which 41.9% had myopia. Myopia was more common in older children (14.8% in 5- to 7-year olds, 59.0% in 17- to 19-year olds). Asian/Pacific Islander patients (OR 1.64, CI 1.58–1.70) had an increased rate of myopia compared to White patients as did African Americans to a lesser extent (OR 1.08, CI 1.03–1.13). Median neighborhood household income of $25,000–40,000 was associated with lower rates of myopia (OR 0.90, CI 0.83–0.97) compared to median neighborhood household incomes less than $25,000. Having at least 60 min of daily exercise was associated with lower prevalence of myopia (OR 0.87, CI 0.85–0.89). Discussion: Myopia was common in this large and diverse Southern Californian pediatric cohort. The prevalence of myopia increases with age. Asian children are at highest risk for myopia. Exercise is associated with a lower rate of myopia and represents an important potentially modifiable risk factor that may be a target for future public health efforts. Keywords: children, epidemiology, exercise, refractive error, myopia, pediatrics, prevalence, public health

Obesitas sentral merupakan ancaman bagi kesehatan masyarakat yang ditandai dengan kelebihan berat badan dan penumpukan lemak pada bagian perut. Bisa dialami oleh siapapun akibat perilaku berisiko dan lingkungan meliputi pola makan dan gaya hidup kurang aktifitas. Termasuk penenun sebagai kelompok masyarakat dengan jenis pekerjaan yang berisiko menyebabkan obesitas sentral. Bentuk upaya penanggulangan masalah ini dapat melalui kegiatan promosi kesehatan yaitu pemberian informasi kesehatan dengan layanan pesan singkat pada telepon seluler dan konseling kelompok. Tujuan: untuk mengetahui pengaruh layanan pesan singkat pada telepon seluler dan konseling kelompok terhadap pengetahuan penenun tentang obesitas sentral. Metode: penelitian ini adalah eksperimen semu dengan rancangan pre-test dan post-test. Ada tiga kelompok intervensi yaitu layanan pesan singkat, konseling kelompok, dan kontrol. Subjek penelitian adalah penenun yang obesitas sentral sebanyak 30 responden. Analisis menggunakan uji paired t-test dengan tingkat kepercayaan 95 persen. Hasil: intervensi layanan pesan singkat lebih besar berpengaruh dibandingkan konseling kelompok terhadap peningkatan pengetahuan tentang obesitas sentral dengan p= 0,001. Kesimpulan: diharapkan Dinas Kesehatan Pematangsiantar agar merancang strategi pencegahan obesitas sentral pada masyarakat menggunakan media layanan pesan singkat.

Developing a laboratory scale or pilot scale chemical process into industrial scale is not trivial. The direct conversion of CO2 to methanol, and concomitant production of hydrogen from water electrolysis on large scale, are no exception. However, when successful, there are certain benefits to this process over the conventional process for producing methanol, both economic and environmental. In this article, we highlight some aspects that are unique to the process of converting pure CO2 to methanol. Starting from pure CO2 and a separate pure source of H2, rather than a mixture of CO, CO2, and H2 as is the case with syngas, simplifies the chemistry, and therefore also changes the reaction and purification processes from conventional methanol producing industrial plants. At the core of the advantages is that the reaction impurities are essentially limited to only water and dissolved CO2 in the crude methanol. In this paper we focus on several aspects of the process that direct conversion of CO2 to methanol enjoys over existing methods from conventional syngas. In particular, we discuss processes for removing CO2 from a methanol synthesis intermediate product stream by way of a stripper unit in an overhead stream of a distillation column, as well as aspects of a split tower design for the distillation column with an integrated vapo-condenser and optionally also featuring mechanical vapor re-compression. Lastly, we highlight some differences in reactor design for the present system over those used in conventional plants.

We report a 56-year-old woman who had an unruptured posterior communicating artery aneurysm. Given the size and location of the aneurysm, as well as her history of smoking and age, she received endovascular treatment with the pipeline embolization device (PED; ev3 Endovascular, Plymouth, MN, USA), complicated by intraoperative rupture (IOR). Flow diversion therapy with the PED has become an increasingly popular method of aneurysmal embolization and parent vessel remodeling. While its on-label approval is for large unruptured aneurysms of the internal carotid artery, success in off-label scenarios has been reported, including ruptured aneurysms. IOR complicates endovascular aneurysm treatment and can cause devastating morbidity or mortality, necessitating acute embolization of the hemorrhaging aneurysm. This patient illustrates the feasibility of treating an IOR with a stand-alone flow diversion device by using PED.

Introduction: The emergence of mechanical thrombectomy has extended the time window for treatment of acute ischemic stroke and improved patient outcomes. Our institution developed a patient selection protocol aimed to improve patient outcomes following the procedure. Hypothesis: Implementation of a patient selection protocol based on evidence-based best practices improves patient outcomes following endovascular intervention in acute ischemic stroke. Methods: In January 2015, our institution developed a patient selection protocol for anterior circulation stroke, including patients with a documented large vessel occlusion, an NIH stroke scale ≥6, a pre-morbid modified Rankin Scale (mRS) ≤2, and with the initial groin puncture within 6 hours of stroke onset. Patients were excluded if pre-morbid life expectancy was ≤90 days, CT perfusion demonstrated 2 test, unpaired t test, and multivariable logistic regression analysis where appropriate. Results: Forty patients underwent endovascular treatment prior to protocol implementation with 65 patients treated under the protocol. Protocol implementation resulted in improved rates of TICI 2B/3 revascularization (87.7% protocol, 57.5% pre-protocol; p Conclusions: The development and implementation of a patient selection protocol for endovascular treatment of large vessel occlusion improves revascularization rates and functional outcomes.

Intracranial aneurysms of the pediatric population are rare, but giant fusiform aneurysms (GFAs) of the middle cerebral artery (MCA) are common within this cohort of patients. These aneurysms are difficult to treat and often require advanced microsurgical skills, as they are usually not amenable to direct clipping. Here, we report the successful treatment of a recurrent GFA of the MCA with three telescoping Pipeline Embolization Devices 6 months after attempted clip reconstruction in a pediatric patient.

Background Diffuse intracranial aneurysmal vasculopathy is a rare condition, previously described in patients with human immunodeficiency virus infection. IgG4-related disease (IgG4-RD) is a recognized inflammatory disease of systemic organs, leading to fibrosis of connective tissues. It also has been linked to inflammatory dilating aortic aneurysms, coronary vascular disease, hypophysitis, orbital pseudotumor, and pachymeningitis. It has not yet been described as a cause of diffuse intracranial dilating vasculopathy. Histologically, this disease is characterized by IgG4-plasma cell infiltration, fibrosis, and phlebitis. Case Description A 40-year-old woman presented with acute heart failure, valvular insufficiency, and mycotic coronary aneurysms, concerning for endocarditis. Infectious workup was negative. Concurrent neurovascular workup revealed intracranial aneurysms, appearing mycotic in origin. Despite aggressive treatment for more than 5 years, she suffered multiple episodes of subarachnoid hemorrhage from a progressive dilating intracranial vasculopathy. Serum IgG levels and aneurysm wall pathology were consistent with IgG4-RD. Conclusions This is the first reported case of a diffuse intracranial dilating vasculopathy secondary to IgG4-RD. Recognition of similar pathologic findings in clinical presentation and radiologic workup should prompt further rheumatologic workup and possible immunosuppressive therapies.

Spinal vascular malformations are rare vascular lesions that most frequently present with back pain, radiculopathy, and/or myelopathy. Neurological decline is typically secondary to progressive radiculopathy, myelopathy, venous thrombosis, and stroke. Few case reports have described thoracolumbar spinal vascular malformations that present with both subarachnoid and intraventricular hemorrhage. This is the first reported case of a thoracolumbar spinal vascular malformation presenting with isolated intraventricular hemorrhage on initial imaging followed by acute and fatal rehemorrhage.

Journal de Gynecologie Obstetrique et Biologie de la Reproduction - Vol. 42 - N° 2 - p. 151-158

International audience; Microarray-based comparative genomic hybridization (aCGH) is commonly used in diagnosing patients with intellectual disability (ID) with or without congenital malformation. Because aCGH interrogates with the whole genome, there is a risk of being confronted with incidental findings (IF). In order to anticipate the ethical issues of IF with the generalization of new genome-wide analysis technologies, we questioned French clinicians and cytogeneticists about the situations they have faced regarding IF from aCGH. Sixty-five IF were reported. Forty corresponded to autosomal dominant diseases with incomplete penetrance, 7 to autosomal dominant diseases with complete penetrance, 14 to X-linked diseases, and 4 were heterozygotes for autosomal recessive diseases with a high prevalence of heterozygotes in the population. Therapeutic/preventive measures or genetic counselling could be argued for all cases except four. These four IF were intentionally not returned to the patients. Clinicians reported difficulties in returning the results in 29% of the cases, mainly when the question of IF had not been anticipated. Indeed, at the time of the investigation, only 48% of the clinicians used consents mentioning the risk of IF. With the emergence of new technologies, there is a need to report such national experiences; they show the importance of pre-test information on IF.

Auditory neuropathy (AN) is defined as a sensorineural hearing impairment (HI) characterized by preserved cochlear outer hair cell function with normal otoacoustic emissions but abnormal or absent brainstem evoked potentials. The prevalence of AN in HIs remains to be established and its pathophysiology has not been determined. Several environmental and genetic causes have been identified, but the majority of cases remain unexplained. In the last 10 years, many genes have been identified in isolated and/or syndromic HI. Some of them (OTOF, PJVK, DIAPH3, OPA1, FXN, PMP22, ERCC6, ERCC8, SLC19A2 and TIMM8A, for example) are responsible for phenotypes corresponding to the AN definition. This review will focus on isolated and syndromic forms of AN for which the causative genes have been identified.

We determined the efficiency of thermoregulation by the southernmost liolaemids Liolaemus sarmientoi and L. magellanicus from Patagonia, Argentina (51°S), by measuring body ( T b ), microenvironmental, and operative temperatures in the field, and preferred body temperatures in the laboratory ( T pref ). L. sarmientoi was found to be a poor thermoregulator, whereas L. magellanicus was deemed to be a constrained thermoconformer. Among all known species of Liolaemus , L. sarmientoi and L. magellanicus had the lowest T b' s when tested in the field; however, their T pref' s were similar to other liolaemids. These data suggest that these southernmost liolaemid species have not evolved appropriate thermoregulatory behaviors or made adequate physiological adaptations to face the extreme thermal challenges of their environment.

To report on the outcomes of sequential bilateral cochlear implantation (CI) in children with inner ear malformation. The study design is a retrospective case study. The setting is a tertiary reference center. Two children presenting a profound bilateral congenital hearing loss with bilateral hypoplasia of the cochleovestibular nerves and hypoplasic external semicircular canal had a cochlear implant at respectively 16 months and 33 months. A second implant was proposed at respectively 17 and 20 months after the first implant. The main outcome measures are audiometry, perceptive results in closed and open set words (CSW and OSW) and oral production at follow-up. The first cochlear implant gave respectively mean thresholds at 60 dB and 70 dB. Bilateral CI showed mean threshold at respectively 40 dB and 55 dB. In case 1, perceptive assessment was 83% and 70% in respectively CSW and OSW with oral production and comprehension of sentences after 1 year follow-up. In case 2, the perceptive assessment showed no perceptive or linguistic evolution at 6 months follow-up. In cochleovestibular nerve hypoplasia, bilateral implantation could be discussed in cases of limited result after unilateral implant.

The quasicrystalline structures of alloys with nominal compositions of Al72Ni13.4Co14.6 and Al72.3Ni7.8Co19.8 were characterized by X-ray diffraction, transmission electron microscopy and scanning electron microscopy. For catalytic application, the solids were leached with an alkaline NaOH solution and tested at 373 K with two model reactions under atmospheric pressure: hydrogenation of crotonaldehyde and acetonitrile. The catalytic activities of these leached alloys were compared to that of a Raney nickel reference catalyst. Catalysts prepared from quasicrystals showed high catalytic activities and high selectivities towards butanal (in crotonaldehyde hydrogenation) and ethylamine (in acetonitrile hydrogenation).

This paper presents the improvement of reactive power and voltage in fourteen bus system using TCTC and STATCOM. Flexible AC transmission systems (FACTS) are the option to mitigate the problem of overloaded lines due to increased electric power transmission by controlling power flows. In this work, combined controller based on optimal power flow (OPF) with multiple objectives is derived in order to provide secure transmission and reduces transmission losses. Static compensator and thyristor-controlled tap changer are two such compensators belonging to FACTS devices are used in this work. The fourteen bus system with closed-loop-controlled STATCOM and TCTC is modeled and simulated.

Objective: To determine the feasibility and efficacy of occipital nerve stimulation (ONS) in patients with refractory headaches secondary to idiopathic intracranial hypertension (IIH). Background: IIH is a syndrome characterized by elevated intracranial pressures in the absence of a mass lesion. These patients typically present with chronic and intractable headaches. Cerebrospinal fluid (CSF) diversion fails in relieving the headache in a significant proportion of this population. ONS has been shown to be effective in medically refractory headaches and to our knowledge, has not been attempted as a therapeutic modality in this population. Methods: Four patients with occipital predominant chronic daily headaches and IIH who failed medical management underwent bilateral ONSs. Octopolar percutaneous electrodes were implanted in the defined area of pain. Visual Analog Scale (VAS) was used as an outcome measure. Patient demographics and surgical complications were also reviewed in this retrospective study. Following the trial period, all patients had >50% pain reduction resulting in permanent implantation. Results: All 4 patients had an average improvement of their VAS scores by 75%, with 85% spatial coverage and the remainder of the uncovered region being frontal. Sustained benefits were seen up to 3 years of follow-up. One patient had a lead erosion requiring removal followed by delayed re-implantation and another lost treatment efficacy at 2 years resulting in explantation. One patient required CSF diversion due to visual threat during the follow-up period but maintained sustained benefit from her ONS. Conclusions: Bilateral ONS may be a useful treatment option in the management of selected patients with IIH, after standard surgical interventions have been attempted. Bilateral ONS may provide therapeutic option for management of residual headaches in these complicated patients.

La hipoacusia es la discapacidad sensorial mas frecuente, y su etiologia es genetica en la mayor parte de los casos. Varias decenas de genes son responsables de las formas pre o poslocutivas de hipoacusia aislada (no sindromica), y se han descrito centenares de sindromes con hipoacusia. En la actualidad, 33 genes (y cuatro mutaciones mitocondriales) se identifican en las hipoacusias no sindromicas, y mas de 100 en las sindromicas. Se ha desarrollado un diagnostico molecular sistematico para algunos de estos genes, sobre todo para el gen de la conexina 26, GJB2, el principal causante de las hipoacusias congenitas. Es fundamental realizar de forma sistematica un estudio clinico y con pruebas complementarias para orientar la estrategia del diagnostico molecular y el consejo genetico.

A series of isostructural dimeric manganese complexes of the type [(Me(4)dtne)Mn(2)(mu-O)(2)(mu-R)](2+)(X(-))(2) have been prepared and characterized. The dimanganese cores of these complexes are rigidly held together by the hexadentate ligand Me(4)dtne (Me(4)dtne = 1,2-bis(4,7-dimethyl-1,4,7-triazacyclonon-1-yl)ethane). Molecular structures for the entire series have been obtained by X-ray diffraction measurements, of which complexes 2 (R = (-)O(2)BPh), 3 (R = (-)O(2)C-PROXYL), 4 (R = (-)O(2)C-TEMPO), and 5 (R = (-)O(2)BPhNIT) are reported here (HO(2)C-PROXYL = 3-carboxy-2,2,5,5-tetramethylpyrrolidin-1-yloxy; HO(2)C-TEMPO = 4-carboxy-2,2,6,6-tetramethylpiperidin-1-yloxy; and HO(2)BPhNIT = 2-(4-(dihydroxyboranyl)-phenyl)-4,4,5,5-tetramethyl-3-oxyimidazolidin-1-oxide). The structures of 1 (R = (-)OAc) and 6 (R = (-)O(2)CPhNIT) have been reported previously (HO(2)CPhNIT = 2-(4-carboxyphenyl)-4,4,5,5-tetramethyl-3-oxyimidazolidin-1-oxide). All complexes exhibit several redox states, which have been investigated by electrochemistry. Complexes 1, 3, 4, and 6 contain a mixed-valent Mn(III)Mn(IV) core with an isolated magnetic ground state of S = 1/2. The exchange coupling between the manganese ions is strong throughout the series (J approximately -130 +/- 10 cm(-)(1), H = -2JS(1)S(2)). The radical complexes 3, 4, and 6 exhibit, in addition, long-range exchange interaction (6.9, 7.7, and 8.8 A, respectively) between the organic radical and the dimanganese core. The intramolecular anisotropic coupling was determined from cw-EPR line shape analyses at S-, X-, and Q-band frequencies and from the intensity of half-field signals detected in normal- and parallel-mode (J(d,)(z)() = -120 x 10(-)(4), -105 x 10(-)(4), and -140 x 10(-)(4) cm(-)(1), for 3, 4, and 6 respectively). Distance information was obtained for the dimanganese core and the organic radicals from these values by using a three-spin dipole model and local spin contributions for the manganese ions.

Several iron(III) complexes with N-methylimidazole (N-MeIm) as the ligand have been synthesized by using N-MeIm as the solvent. Under anaerobic conditions, [Fe(N-MeIm)(6)](ClO(4))(3) (1) reacts with stoichiometric amounts of water in N-MeIm to afford the (mu-oxo)diiron(III) complex, [Fe(2)(mu-O)(N-MeIm)(10)](ClO(4))(4) (3). Exposure of a solution of 3 in N-MeIm to stoichiometric and excess CO(2) gives rise to the (mu-oxo)(mu-carboxylato)diiron(III) species [Fe(2)(mu-O)(mu-HCO(2))(N-MeIm)(8)](ClO(4))(3) (4) and the methyl carbonate complex [Fe(2)(mu-O)(mu-CH(3)OCO(2))(N-MeIm)(8)](ClO(4))(3) (5), respectively. Formation of the formato-bridged complex 4 upon fixation of CO(2) by 3 in N-MeIm is unprecedentated. Methyl transfer from N-MeIm to a bicarbonato-bridged (mu-oxo)diiron(III) intermediate appears to give rise to 5. Complex 3 is a good starting material for the synthesis of (mu-oxo)mono(mu-carboxylato)diiron(III) species [Fe(2)(mu-O)(mu-RCO(2))(N-MeIm)(8)](ClO(4))(3) (where R = H (4), CH(3) (6), or C(6)H(5) (7)); addition of the respective carboxylate ligand in stoichiometric amount to a solution of 3 in N-MeIm affords these complexes in high yields. Attempts to add a third bridge to complexes 4, 6, and 7 to form the (mu-oxo)bis(mu-carboxylato)diiron(III) species result in the isolation of the previously known triiron(III) mu-eta(3)-oxo clusters [[Fe(mu-RCO(2))(2)(N-MeIm)](3)O](ClO(4)) (8). The structures of 3, 4, 6, and 7 allow one, for the first time, to inspect the various features of the [Fe(2)(mu-O)(mu-RCO(2))](3+) moiety with no strain from the ligand framework.

Connexins are the protein subunits of gap junction channels that allow a direct signaling pathway between networks of cells. The specific role of connexin channels in the homeostasis of different organs has been validated by the association of mutations in several human connexins with a variety of genetic diseases. Several connexins are present in the mammalian cochlea and at least four of them have been proposed as genes causing sensorineural hearing loss. We have started our functional analysis by selecting nine mutations in Cx26 that are associated with non-syndromic recessive deafness (DFNB1). We have observed that both human Cx26 wild-type (HCx26wt) and the F83L polymorphism, found in unaffected controls, generated electrical conductance between paired Xenopus oocytes, which was several orders of magnitude greater than that measured in water-injected controls. In contrast, most recessive Cx26 mutations (identified in DFNB1 patients) resulted in a simple loss of channel activity. In addition, the V37I mutation, originally identified as a polymorphism in heterozygous unaffected individuals, was devoid of function and thus may be pathologically significant. Unexpectedly, we have found that the recessive mutation V84L retained functional activity in both paired Xenopus oocytes and transfected HeLa cells. Furthermore, both the magnitude of macroscopic junctional conductance and its voltage-gating properties were indistinguishable from those of HCx26wt. The identification of functional differences of disease causing mutations may lead to define which permeation or gating properties of Cx26 are necessary for normal auditory function in humans and will be instrumental in identifying the molecular steps leading to DFNB1.

As part of our attempts to prepare FeIII complexes with “tunable” spin states, we have synthesized three novel six-coordinate FeIII complexes containing both carboxamido nitrogen (Namido) and phenolato oxygen (Ophen) donors in their ligand framework. Since it has already been shown that carboxamido nitrogen donors usually stabilize FeIII in a low spin configuration, while phenolato oxygens tend to stabilize FeIII in a high spin state, we have incorporated both donor groups in our designed ligands. The syntheses and structures of FeIII complexes with either one or two Namido and Ophen donors are reported in this paper. The properties of these complexes have been compared with the properties of analogous FeIII complexes. The competing effects of Namido and Ophen on the spin state of the FeIII center are discussed in terms of the stabilities of the overall complexes. (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)

Ninety genes have been identified to date that are involved in non-syndromic hearing loss, and more than 300 different forms of syndromic hearing impairment have been described. Mutations in SOX10, one of the genes contributing to syndromic hearing loss, induce a large range of phenotypes, including several subtypes of Waardenburg syndrome and Kallmann syndrome with deafness. In addition, rare mutations have been identified in patients with isolated signs of these diseases. We used the recent characterization of temporal bone imaging aspects in patients with SOX10 mutations to identify possible patients with isolated hearing loss due to SOX10 mutation. We selected 21 patients with isolated deafness and temporal bone morphological defects for mutational screening. We identified two SOX10 mutations and found that both resulted in a non-functional protein in vitro. Re-evaluation of the two affected patients showed that both had previously undiagnosed olfactory defects. Diagnosis of anosmia or hyposmia in young children is challenging, and particularly in the absence of magnetic resonance imaging (MRI), SOX10 mutations can mimic non-syndromic hearing impairment. MRI should complete temporal bones computed tomographic scan in the management of congenital deafness as it can detect brain anomalies, cochlear nerve defects, and olfactory bulb malformation in addition to inner ear malformations.

Basilar artery aneurysms account for a small percentage of intracranial aneurysms; however, they are a diverse group of lesions necessitating different treatment techniques for those that are ruptured and unruptured. Basilar apex aneurysms are the most common type and are frequently wide-necked, necessitating stent-assisted coiling or balloon remodeling. Other techniques have evolved to forego stenting in acutely ruptured wide-necked aneurysms. The prevention of delayed thromboembolic complications with dual antiplatelet therapy in patients with stents is critical. After treatment, basilar aneurysms require close follow-up to ensure complete occlusion. Basilar apex aneurysms often require delayed re-treatment, especially when previously ruptured.

The management of intracranial aneurysms has evolved significantly over the past 2 decades. Anterior communicating artery aneurysms (AComAAs) represent a common and often challenging problem for physicians and patients. Experience and technological advances have broadened the indications for endovascular treatment of all aneurysms. Balloon-mounted catheters and intracranial stents are 2 technological advancements that have made the treatment of previously uncoilable aneurysms feasible. As with all intracranial aneurysms, complete angiographic occlusion remains the goal of care. Balancing the risks of thromboembolic complications with decreasing the risk of hemorrhage, especially in acutely ruptured aneurysms, represents an objective for vascular neurosurgeons.

Spinal vascular malformations are rare vascular lesions that most frequently present with back pain, radiculopathy, and/or myelopathy. Neurological decline is typically secondary to progressive radiculopathy, myelopathy, venous thrombosis, and stroke. Few case reports have described thoracolumbar spinal vascular malformations that present with both subarachnoid and intraventricular hemorrhage. This is the first reported case of a thoracolumbar spinal vascular malformation presenting with isolated intraventricular hemorrhage on initial imaging followed by acute and fatal rehemorrhage.

In its deprotonated form, the ligand N,N′-bis[2-(2-pyridyl)methyl]pyridine-2,6-dicarboxamide (MePy3PH2, where the Hs represent the dissociable amide nitrogens) coordinates to Cu(II) as one strand of a short double helix. The crystal structure of the title complex, bis-(MePy3P)dicopper(II) [Cu2(MePy3P)2], has been determined. The binuclear structure of [Cu2(MePy3P)2] is in contrast to the monomeric Cu(II) complex [Cu(Py3P)] in which the ligand N,N′-bis[2-(2-pyridyl)ethyl]pyridine-2,6-dicarboxamide (Py3PH2) differs from MePy3PH2 by only a single methylene linker. The helical structure of [Cu2(MePy3P)2] has now been added to the rapidly growing number of spontaneously forming helical assemblies, for which crystal structures have been determined.

The small organic molecule pyridine-2,6-dicarboxamide, although known in the literature for some time, exhibits interesting and previously unexplored intermolecular and intramolecular hydrogen bonding both in solid state and in solution. With the aid of X-ray crystallography and variable-temperature NMR spectroscopy, we here demonstrate the presence of a very strong hydrogen bonding network for this molecule both in condensed state and solution. Furthermore, a novel extended hydrogen bonding graph-set has been derived for this molecule in crystalline state. Comparison of pyridine-2,6-dicarboxamide with 1,3-benzenedicarboxamide, where the intramolecular hydrogen bonding to the pyridine ring in the former has been removed, yields a different intermolecular hydrogen bonded structure in the solid state. A new graph-set has been determined for the extended structure of 1,3-benzenedicarboxamide in the solid state. In solution, 1,3-benzenedicarboxamide is shown to maintain a hydrogen bonding pattern that is weaker than that observed with pyridine-2,6-dicarboxamide. Replacement of one hydrogen on each carboxamide nitrogen of pyridine-2,6-dicarboxamide by a methyl group also alters the extended structure to a significant extent. In N , N ′-dimethyl-2,6-pyridinedicarboxamide, the three-dimensional hydrogen bonding pattern observed with pyridine-2,6-dicarboxamide all but collapses to one-dimensional chains.

As part of our continuing effort to develop the chemistry of iron(III) complexes of ligands that employ carboxamido nitrogens to bind the metal center, we have synthesized the designed ligand N,N′-bis(2-hydroxyphenyl)pyridine-2,6-dicarboxamide (POPYH4, Hs are dissociable phenolic and carboxamido hydrogens). Reactions of the completely deprotonated POPY4− with certain iron(III) starting materials in DMF afford pentagonal bipyramidal complexes of the type [Fe(POPY)X2]n− (X=1-MeIm, SCN−), in which the pentadentate POPY4− ligand occupies the equatorial plane. When smaller amounts of base are used, the partially deprotonated POPYH2 2− ligand gives rise to the tetrahedral bis complex [Fe(POPYH2)2]− in which only the phenolic oxygens of the ligand are bound to iron(III). With [Fe2OCl6]2−, one obtains [Fe(POPYH2)(Cl)]2O, a new species that contains a (μ-oxo)diiron(III) core. Here also, POPYH2 2− employs the phenolic oxygens to bind iron and acts as a bidentate ligand. The structures of these complexes have been determined by X-ray crystallography. The conditions for interconversions among the four complexes have also been elucidated. Both [Fe(POPY)X2]n− complexes with coordinated carboxamido nitrogens are stable in air and in aqueous solution. The redox properties of these species indicate that ligated carboxamido nitrogens provide enhanced stability to iron(III) centers.